Update django-floppyforms to 1.7.0

[pyup-bot]

There's a new version of django-floppyforms available.
You are currently using 1.6.0. I have updated it to 1.7.0

Changelog

1.7.0

* `171`_: Fix path to GIS widget images in ``openlayers.html`` template. The
 files coming with Django admin where used, but the naming changed in 1.9. We
 vendor these know to have better control over it.
* `174`_: Support for setting your own Google Maps key in the
 ``BaseGMapWidget``. `See the documentation
 <http://django-floppyforms.readthedocs.io/en/latest/geodjango.html>`_ for
 details

.. _171: https://github.com/gregmuellegger/django-floppyforms/issues/171
.. _174: https://github.com/gregmuellegger/django-floppyforms/pull/174



### 1.6.2

• 169_: Use the attributes ClearableFileInput.initial_text,
  ClearableFileInput.input_text,
  ClearableFileInput.clear_checkbox_label to determine the used text in the
  template. This was inconsistent so far with Django's behaviour.

.. _169: jazzband/django-floppyforms#169

1.6.1

* `167`_: Fix django-floppyforms' ``CheckboxInput.value_from_datadict`` which
 was inconsistent with Django's behaviour.

.. _167: https://github.com/gregmuellegger/django-floppyforms/issues/167

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖